Vibrating screen with spring beam

ABSTRACT

A separating and feeding means comprising a body mounted by spring beams to a base member, the body having a plurality of screens mounted thereon which separate larger from smaller particles, the screens being arranged in vertical separation from one another. Vibration-applying means are arranged to oscillate said body and screens about the virtual pivot axis of the spring beams to cause the particles to move linearly along the screen. In one embodiment a movable guide vane is mounted on the body to direct the flow of material from one screen to a discharge chute, with a similar guide vane being provided for the other screen or screens, said chutes being interconnected so that the same type of part can be discharged to the same physical location regardless of the relative sizing of the particles. In another embodiment an opening is provided through the lower section of the body and through the lower screen leading to a multiexit discharge chute, with a guide vane located within the chute to direct the particle flow selectively to an exit.

United States Patent [72] Inventor Max Isaacson 2,645,189 7/1953 Hansalik 209/264 X 420 West Nottingham Road, Dayton, Ohio 3,130,831 M hOOI 2 7 X 45405 3,169,108 2/1965 Dietert 209/175 [211 App]. No. 821,215 3,173,664 3/1965 lsaacson et al 259/72 1 Filed y 2,1969 FOREIGN PATENTS [45] Patented 50,516 7/1889 Germany.: 209/215 Continuation-impart of application Ser. No. 91 992 1/1 896 Germany... 209/264 685,544, Nov. 27, 1964, now abandoned. 752263 7/1933 France 209/326 This application May 2, 1969, Ser. No. 821,215 Primary ExaminerFrank W. Lutter Assistant Examiner-Robert Halfer Attorney-Milton E. Gilbert [54] VIBRATING SCREEN WITH SPRING BEAM 2 Claims, 1 1 Drawing Figs.

ABSTRACT: A separating and feeding means comprising a [52] US. Cl 209/256 b d mounted b s rin beams to a base member, the body [51] I t Cl /3 9/348 209/368 having a plurality of screens mounted thereon which separate n o larger from smaller Particles, the Screens being arranged in g vertical separation from one another. Vibration-applying [so] new 207/275 means are arranged to oscillate said body and screens about 3 3 the virtual pivot axis ofthe spring beams to cause the particles 415 0 262. 264 332 255-259 to move linearly along the screen. In one embodiment a mova- 3 198/220 P 42; 51/7 ble guide vane is mounted on the body to direct the flow of 163 74/26 61 P material from one screen to a discharge chute, with a similar [56] Reierences Cited guide vane being provided for the other screen or screens, said 1 chutes being interconnected so that the same type of part can UN TED STATES PATENTS be discharged to the same physical location regardless of the 542,337 7/1 5 Fixler.. 2 /33 relative sizing of the particles. In another embodiment an 935,216 9/1909 Melkle ohn 209/368 X opening is provided through the lower section of the body and 993,439 7/191 1 WllfOrd o 17 through the lower screen leading to a multiexit discharge 1,479,904 1/1 24 Ffilker 209/332 chute, with a guide vane located within the chute to direct the 2,076,195 4/1937 Flckel 209/329 X particle flow selectively to an exit.

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ATTORNEY VIBRATING SCREEN WITII SPRING BEAM This application is a continuation-impart of application Ser. No. 685,544 now abandoned, and filed Nov. 24, 1967.

BACKGROUND Vibrating screen devices have been known previously which have employed a plurality of screen elements. Such devices have also been used with various media-treating equipment to receive, separate and discharge such media. However, such devices have usually been single purposed in the sense that they required extensive rearranging and changing of parts to accommodate their use with various combinations of media sizes, and were particularly unsuitable for use with continuous feed-recycling systems. Such devices moreover were of inordinate length, which was required in order to permit separation of parts in larger loads.

OBJECTS It is one object of the invention to provide a novel vibrating screen which ensures that the treated parts will be separated and discharged rapidly in a minimum linear distance.

A further object of the invention is to provide a vibrating screen in which parts will be discharged from the same location on the screen regardless of the relative size of said parts to the treating media.

Another object of the invention is to provide a novel vibrating screen which permits greater and more rapid movement of parts thereon.

Still another object of the invention is to provide a vibrating screen on which parts are moved thereon in a uniform linear motion and are urged to tumble in a desired direction.

These and further objects of the invention will become more readily apparent from a reading of the specification following hereinafter and from an examination of the drawings, in which:

LISTING OF DRAWINGS FIG. 1 is a side view, partially in phantom and partially in section, of the novel vibrating screen of the invention;

FIG. 2 is a front view of the vibrating screen of FIG. 1

FIG. 3 is a top plan view, partially in schematic, showing the upper screen deck of the screen of FIG. 1;

FIG. 4 is a top plan view, partially in schematic showing the lower screen deck of the screen of FIG. 1;

F IG. 5 is a front view of another embodiment of a vibrating screen of the invention;

FIG. 6 is an end view of the vibrating screen of FIG. 5;

FIG. 7 is a side view of the embodiment of FIG. 5 showing another form of multiexit discharge chute,

FIG. 8 is a partial rear view of the discharge chute of FIG. 7,

FIG. 9 is a side view of another embodiment of a vibrating screen of the invention; and

FIGS. 10 and 11 are schematic diagrams illustrating the unifonn motion of the particles on the screen.

DETAILED DESCRIPTION OF DRAWINGS One form of vibrating screen of the invention comprises a base 300, which may be provided with resilient mounts 302, 302. Mounted upon the base 300 is the screen body 304. The connection is through I-beam springs 306, 308; one being mounted at each side of the body 304. The horizontal portions of the springs are affixed at their upper portions to the screen body and at their lowerportions to the base, as shown at 310 and 312, respectively. Dependingly mounted to the body 304 is an armature 314 of ferremagnetic material. Arranged in opposed relationship to this armature are electromagnets 316, 318 which cooperate with the armature to cause the screen body to oscillate in the manner in which the tub is oscillated in vibrating deburring machines of the type as shown in US. Pat. No. 3,l73,664, issued on Mar. l6, I965 to Max Isaacson and Joseph Flatt, and entitled Vibrator." Large amplitudes of motion are thus transmitted to the screen body, especially at the end upon which media and parts are loaded onto the screen. More rapid separation and movement of parts can thus be accomplished.

The screen body 304 contains an upper deck 320 and a lower deck 322. These decks are appropriately formed of heavy screen mesh material mounted upon a frame. The upper deck 320 has a screen of larger mesh 324 than the mesh 326 of the lower deck 322. The decks are provided with guide vanes, vane 328 being arranged on the upper deck and vane 330 being arranged on the lower deck. The guide vane 328 is pivotally mounted on the shaft 332, and the guide vane 330 is pivotally mounted on the shaft 334, for purposes as explained hereinafter. A deck of solid construction 336 is arranged to receive the guide vane 328 and is aligned with the upper screen deck 320. A similar solid deck 338 is aligned with the lower screen deck 322 and receives the guide vane 330.

Discharge chutes 331 and 333 are fixedly mounted to the base 300 and are so located as to receive discharged material from decks 336 and 338.

The vibrating screen of the invention may be employed with a continuous feed vibrating deburring machine which is arranged to discharge processed parts and media onto the screen. The screen then serves to separate the parts from the media into a finished parts hopper and into a media storage bin, the latter being re-used in the continuous feed cycle. In such a device it is desired that at all times the parts be directed to the same parts bin and the media be returned to its storage bin, regardless of the relative size between the parts and media. The movable guide vanes enable this to be accomplished. As shown in the drawings the larger parts that do not pass through the mesh 324 will be directed by the guide vane 328 to the chute 331, and the smaller media will will be directed by the guide vane 330 to the chute 333 for discharge on to the conveyor. If the media is larger than the parts, then the guide vane 328 is positioned to the dotted line position shown in FIG. 3 and the guide vane 330 is positioned to the dotted line position shown in FIG. 4. Since the media will now remain on the upper deck, the repositioned guide vane 328 will now direct the media to the chute 333 and the parts will fall through to the lower deck and be directed by guide vane 330 to the chute 331. Thus, no matter what the relationship in size between the parts and media, the guide vanes can be so positioned that the parts will always flow to the parts bin and the media will always be returned to the media storage bin. The media may be flushed clean on the table body 304 itself by properly directing streams of water thereon, if desired.

The specific arrangement of the I-beam springs 306, 308 with respect to the positioning of the screen is important. The upper screen deck 320 is located above the virtual pivot axis provided by the spring beams. This relationship is more clearly understood with reference to the schematic diagrams of F IGS. 10 and 11. As shown therein, a screen S is located above the pivot axis P provided by spring beams. Considering the motion of a particle m which is at a radial distance r from the axis P, and vertically thereabove the distance y, it is seen that when the screen S is vibrated through an angle 0 about the pivot P, and where 0,, is the angular amplitude:

where f the frequency of vibration of said screen. The linear motion 1 of any point on the screen which is r distance from pivot P is then:

The peak acceleration of the particle m which occurs at the end of the stroke), is:

peak acceleration a 411- f r and the accelerating resultant force F, which moves the particle m in an upward direction is F ma 41rff rm and the horizontal component urging the mass m to move in the horizontal direction shown is:

It is thus seen that the horizontal component in the direction shown is uniform all along the screen since it is independent of the distance r. Consequently, locating the screen S above the pivot axis P tends to produce uniform horizontal forces in the direction shown, which are imparted to the particles on the screen regardless of their position when it is vibrated by the spring beam arrangement shown. When the screen vibrates downward, the particles m will not tend to be accelerated in the reverse direction. This cancels out the horizontal motion already achieved because the particle will be unable to follow the high downward velocity of the vibrating screen and will therefore tend to fall vertically with only little horizontal component of velocity.

Although not shown, it is clear that the spring beams need not be placed at the end of the screen body, but may be placed also inwardly from the ends, e.g. at the center, as long as the virtual pivot axis is below the plane of the screen.

Considering the embodiment of FIG. 5, the vibrating screen comprises a base 400, which is provided with the resilient mounts 402, 403. The rear mounts 403 may be larger than the front mounts 402 in order to tilt the screen body and the screen elements therein from a horizontal posture. Mounted upon the base 400 is the screen body 404, which is connected to the base through spring I-beams 406, 408, one being mounted on each end of the base 400. As shown more clearly in FIG. 6, the upper horizontal portions 407 are affixed to extensions 411 of the body 404, whereas the lower horizontal portions 409 of the spring beam 406 are affixed to the base 400.

Mounted to the base 400, on a shelf 405 is the electromagnet 416, which cooperates with the armature 414, shown as a paddlelike plate affixed to depending ribs 415, 417 and 419, which are welded or otherwise affixed to the screen body 404. The armature 414 is so located with respect to the virtual pivot axis provided by the spring beams 406, 408 that the centerline of the armature lies substantially in a plane passing through the pivot axis and the armature lies near the virtual pivot axis. This serves to minimize the mass inertia of the vibrating screen body.

As shown in the drawings, the screen body 404 may be provided with a set of three screen or screen decks 420, 422 and 424 extending the length of the screen body and of progressively decreasing hole size. It may be desireable, as in the case of cup-shaped parts, to cause the treated pans to tumble or move in a desired direction. For this purpose the upper screen 420 may be provided with protuberances 421, which may be in the form of corrugations or wedge-shaped members to urge such parts to roll over. This is necessary in order to release any entrapped media (which is smaller in size) from within the parts. These protuberances can be shaped in any desired manner to cause gyration of the parts and can be arranged so that they cause the parts to move linearly along the screen.

An alternate form of discharge chute is shown in FIGS. 6 and 7. This chute 430 may be suspended from the screen body itself, i.e. it may be formed in the screen body in depending fashion, and is provided with two exit passages 432 and 434. A single guide vane 436 may be pivotally mounted as at 438 within the chute 430 to control the egress of parts or media from the screens to the exits. The alternate position of the vane 436 is shown in dotted lines at 440, in which location it shuts off the exit passage 434, whereas in the solid line position shown in FIG. 8 the exit passage 432 is closed off.

As shown in FIG. 6, the screens are curved concavely in a direction transverse to the flow of the parts and media. The tilted arrangement shown in FIG. 5 cooperates with this concave form to induce a forward helical motion of parts along the screen. As shown in the FIG. 7, the mouth of the chute 430 is widened as at 442 to encompass a selected area of the second screen deck. It is obvious that if desired the chute can be made wider mouthed and can be located at any other desired position, which is selected so that it will receive the parts as they fall through the screens. Also, the mouth of the chute can be perforated so as to permit fines and water to be removed to the lower screen deck 424 of the screen body or the lowermost portion 444 of the screen body itself.

An even more simplified version of a screen according to the invention is shown in FIG. 9, wherein the screen body 504 is mounted directly to the side of a vibrating tub of a deburring machine such as shown in the aforementioned U.S. Pat. No. 3,173,644. Since the tub 100 experiences vibratory impulses of the type im imposed upon the screen body in the foregoing embodiments such vibrations can be transmitted to the screen body 504 if it is affixed to the tub. In the simplified version shown, a bracket 506 is bolted to the body 504 by the bolts 508. The upper portion of the bracket 506 may be bolted by bolts 510 to depending ears 512 on the chute 102 of the tub 100. A set of screen decks 520 and 522 may be provided, with the lower screen deck 522 formed into a funnel shape with a central opening 542 leading to a discharge chute 530, similarly formed as described above in connection with the showing of FIGS. 5 through 8. In the simplified arrangement of FIG. 9, the parts are removed from the top screen deck 520 (which may also be curved transversely), and the media are removed from the inclined lower deck 522 through the opening to the discharge chute 530 (which may be a single-exit duct as shown). The bottom surface 524 of the screen body 504 may serve to catch the fines and water.

Although I have described several specific embodiments and arrangements of the various features of my invention, it should be understood that parts may be rearranged, substituted or eliminated while still coming within the spirit and scope of the invention. Although the vibrating screen of the invention can be operated at any desired frequency I have found that the most effective results are obtained when the natural frequency is somewhat lower than the applied frequency of the forcing function, so that when a peak load is discharged onto the screen, the natural frequency will more closely approach the applied frequency due to the load and thereby bring into effect a more resonant condition. In this fashion the vibratory amplitudes of the screen body are automatically increased for peak loading of parts within the screen body.

What I claim is:

l. A parts separating and feeding device comprising, in combination:

a substantially planar screen element having an effective working area;

a body having said screen element mounted thereon;

a base member;

spring means including at least one spring beam fixedly connected at one end to said body and at the other end to said base member thereby causing said body to have an angular degree of freedom of motion about the virtual pivot axis of said spring beam, the virtual pivot axis of said spring beam and the plane of said screen being so constructed and arranged as to cause parts to move linearly when said screen is oscillated about said axis;

vibration means for applying impulses to said body to effect oscillations of said screen about said axis and thereby cause separation of said parts according to size, while simultaneously causing said parts to move linearly along the working area of said screen;

said body having at least an upper deck and a lower deck,

said upper deck including a screen, and a first and second exit means each exit means communicating with both of said decks, and directive means associated with each of said upper deck is connected to said second exit means said decks and said first and second exit means, and while said lower deck is connected to said first exit movably mounted as to operate in two modes of opera means. I tion i one d f operation an upper d k 5 m. 2. The separating and feeding mean of claim 1 where said nected in a certain fl w m to said fi t ex means ans 5 directive means are supported from said base member and are said lower deck is connected in a certain flow path to said free from screen second exit means and in the second mode of operation 

1. A parts separating and feeding device comprising, in combination: a substantially planar screen element having an effective working area; a body having said screen element mounted thereon; a base member; spring means including at least one spring beam fixedly connected at one end to said body and at the other end to said base member thereby causing said body to have an angular degree of freedom of motion about the virtual pivot axis of said spring beam, the virtual pivot axis of said spring beam and the plane of said screen being so constructed and arranged as to cause parts to move linearly when said screen is oscillated about said axis; vibration means for applying impulses to said body to effect oscillations of said screen about said axis and thereby cause separation of said parts according to size, while simultaneously causing said parts to move linearly along the working area of said screen; said body having at least an upper deck and a lower deck, said upper deck including a screen, and a first and second exit means each exit means communicating with both of said decks, and directive means associated with each of said decks and said first and second exit means, and movably mounted as to operate in two modes of operation, in one mode of operation an upper deck is connected in a certain flow path to said first exit means and said lower deck is connected in a certain flow path to said second exit means and in the second mode of operation said upper deck is connected to said second exit means while said lower deck is connected to said first exit means.
 2. The separating and feeding means of claim 1 where said directive means are supported from said base member and are free from said screen. 